Doors and windows. A door or a window can be regarded as a line in a 2D floorplan.
Intuitively, we can view them as a special “polygon" with 2 vertices.
This way, our pipeline can be directly adapted to predict doors and windows without architecture modification.
It is only required to increase the room-level queries \(M\)  since more polygons need to be predicted (Fig. REF ).
Alternatively, we could use a separate line decoder to predict doors and windows.
Since a line can be parameterized by a fixed number of 2 vertices, we can either represent them as two-level queries but with a fixed number of corner-level queries (Fig. REF ), or single-level queries (Fig. REF ). The two-level queries variant is simply an adaptation of our polygon decoder.
For the single-level queries variant, we follow LETR [1]} that directly predicts the two end points from the query.
The performance of each variant is analyzed in Sec. REF .
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